Pathogens and Their Drug Resistance in Senile Patients with Lower Respiratory Tract Infection: A Clinical Investigation

OBJECTIVE To investigate the distribution causing lower respiratory tract infection and drug resistance of bacteria and the prevalence of the bacteria producing extended spectrum β lactamases ( ESBLs ) . METHODS The susceptibility to antimicrobial agents was studied with diffusion method on Mueller Hinton medium. The double disk test for ESBLs confirmed all putative ESBLs producing strains. RESULTS A total of 598 strains were obtained from lower respiratory tract in senile patients. From them 439 strains were Gram negative bacilli, the predominant pathogens were Pseudomonas aeruginosa. The susceptibility test showed the resistance of bacteria were markedly increased. Twenty nine isolates of 139 strains Escherichia coli and Klebsiella pneumoniae were ESBLs producing(20.9%). CONCLUSIONS The Gram nagative bacilli were the major pathogens isolated from senile patients with lower respiatory tract infection. The monitoring should be enhanced to give suggestions to rational use of antibiotics.